The UNMC Eppley Cancer Center provides a controlled access Animal Care Shared Resource that supports the research of UNMC Eppley Cancer Center investigators. The facility has a controlled environment with stable temperatures and humidity. It operates as a type IV barrier system, which reduces both the risks of the introduction of diseases into the Animal Care Shared Resource and their spread should they be introduced. The benefits of the barrier system, controlled access and the minimization of disease introduction and spread, has allowed us to establish two units (embryonal stem cell/gene knockout and transgenic mice). The barrier facility also allows completion of the long-term animal experiments carried out by Cancer Center members. All animals coming into UNMC from non-approved sources such as other investigators at other universities must be housed in a quarantine facility before entering the Cancer Center Shared Resource. They are housed there until the Comparative Medicine staff has determined that the animals are free of pathogenic organisms. Priority for use of the Animal Care Shared Resource is given to Cancer Center members. Use of the Animal Care Shared Resource is contingent upon the activities being consistent with Animal Care Shared Resource policies and the maintenance of the barrier system.